In the operation of a centrifugal finishing machine, the contents of the finishing chamber or tub must be removed at the conclusion of the process cycle. A pivoted horizontal axis is generally provided so that the machine tub can be tilted similar to a cement mixer and the contents flow out onto some separation device, conveyor or bin. A manual lever may be used to pull the tub forward for unloading. Presently, a tab, either welded or bolted to the tub, is utilized as a "stop", which holds the machine tub in an upright position. After the contents of the tub are removed, the operator must physically ease the tub back to the "stop" while holding the extra weight of the motor and gearbox on the tub, since the media and parts balance the load. If the operator should slip and accidentally release the handle, the tub will rapidly tilt back to the "stop", possibly causing severe injury to the operator and fracturing the "stop".
In accordance with the invention, a tilting system for centrifugal finishing machines which include a finishing chamber or tub in which parts or work pieces are treated and which is pivoted about a horizontal axis for tilting to remove the parts comprises a hydro-mechanical system which permits free movement from an upright to tilted position and retards movement from a tilted position to a upright position. The hydro-mechanical system preferably includes a hydraulic linear actuator which has a piston rod with pistons at each end and is connected by a rack and pinion arrangement to the tub. A line extends from one end of the actuator to the other and a one way flow control valve is provided in the line. The tilting motion may be applied manually or by power.